<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8"/>
  <title>11_Promise相关面试题4</title>
</head>

<body>
<script>

  new Promise((resolve, reject) => {
    console.log('1')
    resolve()
  })
    .then((res) => {
      console.log('2')
      new Promise((resolve, reject) => {
        console.log('3')
        resolve()
      })
        .then(() => {
          console.log('4')
        })
        .then(() => {
          console.log('5')
        })
      // return undefined
      return new Promise(resolve => {
        resolve()
      })
    })
    .then((res) => {
        console.log('成功')
      },
      (err) => {
        console.log('报错')
      })

  // new Promise((resolve, reject) => {
  //   console.log("7");
  //   resolve();
  // }).then(() => {
  //   console.log("8");
  // });
</script>
</body>

</html>
